J/AJ/132/1372 Chandra observation of NGC 6822 (Tennant+, 2006)
Chandra observation of NGC 6822.
Tennant A.F.
<Astron. J., 132, 1372-1383 (2006)>
=2006AJ....132.1372T 2006AJ....132.1372T
ADC_Keywords: Galaxies, nearby ; X-ray sources
Keywords: galaxies: individual (NGC 6822) - methods: data analysis -
X-rays: galaxies
Abstract:
Chandra observed the nearby dwarf galaxy NGC 6822. There are 70
sources in the Chandra field, two of which are fairly extended and
likely background clusters of galaxies. A third source was resolved by
Chandra that has the same size and position as a known supernova
remnant. The suspected variability detected from this source in
previous missions is shown to be in error. The majority of the
remaining 67 sources are consistent with background sources. Of the 61
sources detected above a completeness limit of 10 events, we estimate
that 9±4±8 are associated with the galaxy, including both
systematic and statistical errors. We compare the X-ray positions of
all sources with various catalogs and Hubble Space Telescope data and
offer tentative identifications for several. Based on the mass and
star formation rate of NGC 6822, we expect only about 10 sources,
mostly high-mass systems.
Description:
NGC 6822 was observed for 28.1ks by Chandra on 2002 November 4. The
I-array CCDs plus S2 were operated in the normal 3.14s time exposure
mode. The S2 chip was mostly used as a background monitor, and since
it was far off-axis did not yield any other useful information about
NGC 6822.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 41 68 Chandra Sources in NGC 6822
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See also:
J/AJ/121/2020 : CTIO and WFPC2 photometry in NGC 6822 (Bianchi+, 2001)
J/AJ/132/378 : HST and UV photometry of NGC 6822 (Bianchi+, 2006)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- [T2006] Source name (SNN)
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 16 F6.3 s RAs Right ascension (J2000)
18 A1 --- DE- Declination sign (J2000)
19- 20 I2 deg DEd Declination (J2000)
22- 23 I2 arcmin DEm Declination (J2000)
25- 29 F5.2 arcsec DEs Declination (J2000)
31- 33 F3.1 arcsec ePos Radius hat encloses the Chandra position
with 90% confidence
35- 37 F3.1 arcsec PSFsig Size of the PSF at this location
39- 41 I3 ct Counts Number of counts detected corrected for the PSF
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Apr-2008